Schools Chancellor Dennis Walcott wants to find out if New York City kids are making the grade. Good.

At the urging of Post columnist Michael Goodwin, Walcott Wednesday launched a probe into grading and promotion in the city’s 1.1 million-pupil system.

The Department of Education nominally ended social promotion in 2004. But as Goodwin wrote, and school employees confirmed, the practice lingers.

One Manhattan high-school staffer told Goodwin that “teachers in [the] school are ‘encouraged’ to pass 80 percent of students, no matter their grades or attendance.” Another wrote that, “Our mandated passing rate is 60 percent.”

A Brooklyn high-school professional told Goodwin, “The administration allows students to run around, go to class for 5 minutes, and we must mark them present . . . We are also encouraged to change attendance of students marked absent up to 2 weeks earlier, looking for ‘proof’ they are absent. So teachers just give up and mark them present.”

It’s vital that Walcott ascertain whether these are just isolated cases or part of a larger pattern.

It’s true that city students have been doing somewhat better on state tests — and the city says that its graduation rates are up.

But Goodwin’s reporting calls even those meager gains into question.

Walcott seems sincere about wanting to get to the bottom of this. He’s invited more whistleblowers to e-mail him: DMWalcott@schools.nyc.gov.